Work on,
My medicine, work! Thus credulous fools are caught;
And many worthy and chaste dames even thus,
All guiltless, meet reproach.
– William Shakespeare
Othello, Act 4, Scene 1. Iago is delighted when a distressed Othello collapses in a fit after he destroys Desdemona’s reputation. Medicine is a rather ironic metaphor for the poisonous words and lies Iago poured into Othello’s ear. He is pleased at how it is working and how easily he can trick gullible fools like Othello.